Closed
Description
Suggestion
TypeScript has a simple guess on whether the input file is in es modules or global script by seeing it includes keywords like import, export. So an empty file becomes non-esm and triggers an error ts(1208): 'file.ts' cannot be compiled under '--isolatedModules' because it is considered a global script file. Add an import, export, or an empty 'export {}' statement to make it a module..
However, as you may know empty files are also valid es modules. I think it is safe to remove this error/warning and just treat an empty file as in esm.
Rollup and esbuild also treat empty files as ESM too.
🔍 Search Terms
IsolatedModules, empty, esm, warning.
✅ Viability Checklist
My suggestion meets these guidelines:
- This wouldn't be a breaking change in existing TypeScript/JavaScript code
- This wouldn't change the runtime behavior of existing JavaScript code
- This could be implemented without emitting different JS based on the types of the expressions
- This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
- This feature would agree with the rest of TypeScript's Design Goals.
⭐ Suggestion
Treat empty files as es modules when "IsolatedModules" is on.